This invention relates to a process for reclaiming residuals produced from the manufacture of decorative high pressure laminates (HPLs), as well as to composite materials obtained by the process.
A decorative HPL is defined by ISO 4586-1 (1987) point 3 as a sheet of layers of paper impregnated with thermosetting resins, the core layers being impregnated with phenolic resins and a surface layer or layers impregnated with aminoplastic resins, and bonded together by means of heat and pressure of not less than 5 MPa, the outer layer or layers on one or both sides having decorative colors or designs.
In manufacturing such plastic laminates for ornamental purposes, a large amount of residuals and scraps of material are produced which must be disposed of. The scrap material mainly finds its origin from the contours of the impregnated paper stack which protrude from the press plates and are trimmed away, paper cutouts produced during various impregnation steps, and powders and/or chips produced upon grinding and/or milling the laminate back side for better glue adhesion in later applications. The disposal of these residuals obviously raises possible environmental pollution problems, as well as cost burdens on the laminate manufacturer.